Longtime BFFs Nick Jonas and Demi Lovato are set to go on the road together in June, but a source tells In Touch that the duo are at war. “Nick thinks she’s partying too much,” says the source, noting that the “Jealous” singer blames the recovering addict’s friendship with rapper Iggy Azalea. “He says he doesn’t recognize her since she started hanging out with Iggy and thinks she’s phoning it in during rehearsals while he’s working his a-- off.” The harsh criticism infuriated Demi, 23. “She screamed that he’s a hypocrite because he won’t stop bringing girls around and can’t focus,” says the source. She also “accused him of faking his passion for music” and only caring about “his image and his abs.” (Hey, leave his abs out of this!)…